Microedus kastcheevi, Shavrin, 2024

Shavrin, Alexey V., 2024, Microedus LeConte, 1874 (Coleoptera: Staphylindae: Omaliinae: Anthophagini), a new genus for the Palaearctic Region, Zootaxa 5443 (2), pp. 205-223 : 214

Microedus kastcheevi sp. n.

( Figs 3 , 22–23 , 30 )

Type material examined. Holotype ♂ ‘ Kazakhstan | Narym Riv., Maimer | 06.08.1986 | V. Kastcheev’ <printed>, ‘HOLOTYPE | Microedus | kastcheevi sp.n. | Shavrin A.V. des. 2024’ <red, printed> ( ZIN).

Paratypes: 9 ♂♂ (one specimen without head and pronotum; one specimen without head), 5 ♀♀: same data as the holotype (1 ♀: cSch; 4 ♂♂, 2 ♀♀: cSh; 5 ♂♂, 2 ♀♀: ZIN); 13 ♂♂ (two specimens without abdomen), 10 ♀♀: ‘SE Kazakhstan, | Dzhungar Mts., Sarkand Riv. | 15.08.2006 | V. Kastcheev’ (3 ♂♂, 2 ♀♀: cSh; 1 ♂, 1 ♀: NME; 1 ♂, 1 ♀: NMW: 1 ♂, 1 ♀: ZMM; 7 ♂♂, 5 ♀♀: ZIN); 2 ♂♂, 4 ♀♀: ‘SE Kazakshtan | Chylik Riv., ur. Sarybastau | 14.06.1988 | V. Kastcheev’ (1 ♂, 1 ♀: cSh; 1 ♂, 3 ♀♀: ZIN). All paratypes with additional red printed label: ‘ PARATYPE | Microedus | kastcheevi sp.n. | Shavrin A.V. des. 2024’.

Redescription. Measurements (n=44): HW: 0.65–0.78; HL: 0.42–0.56; OL: 0.13–0.20; LT: 0.10–0.15; AL (holotype): 2.10; PL: 0.55–0.74; PWmax: 0.85–1.02; PWmin: 0.70–0.88; ESL: 0.92–1.25; EW: 1.35–1.50; MTbL (holotype): 0.85; MTrL (holotype): 0.33 (MTrL 1–4: 0.16; MTrL 5: 0.17); AW: 1.20–1.61; AedL: 0.85–1.00; BL: 3.40–4.95 (holotype: 3.95).

Habitus as in Fig. 3 . Body brown to reddish-brown (some paratypes with distinctly paler elytra and darkened mediobasal portion). Head with moderately dense isodiametric or somewhat transverse microsculpture, distinctly finer in middle and coarser on infraorbital portions (holotype and several paratypes without visible meshes between anteocellar foveae); neck with dense transverse microreticulation; pronotum with dense transverse or isodiametric microsculpture, finer and sometimes indistinct in middle.

Head 1.3–1.5 times as broad as long, with medioapical depression strongly narrowing posteriad; temples long, but distinctly shorter than longitudinal length of eyes. Ocelli located distinctly below level of posterior margins of eyes, about as long as distance between ocellus and posterior margin of eyes or slightly shorter. Punctation fine, denser and larger in middle and on infraorbital portions. Apical segment of maxillary palpi 1.4–1.6 times as long as preapical segment. Antennomeres 4–10 slightly elongate; antennomere 3 slightly longer than 2, 4 slightly shorter and broader than 3, 5–7 slightly longer and broader than 4, 8–10 slightly shorter and broader than 7, apical antennomere distinctly longer than 10, from about middle gradually narrowed toward subacute apex.

Pronotum 1.2–1.3 times as broad as long, 1.3 times as broad as head, from widest anterior portion gradually narrowed posteriad. Punctation dense and fine, sometimes finer and sparser in middle; several paratypes without punctures in mediobasal third.

Elytra 1.2–1.4 times as broad as long, 1.6 times as long as pronotum. Interstices between punctures in middle about as long as distance of one-two nearest punctures, portions of each elytron along suture with finer and sparser or sometimes with very dense punctation.

Abdomen distinctly broader than elytra, with two transverse tomentose spots in the middle of abdominal tergite IV.

Male. Apical margin of abdominal tergite VIII somewhat straight. Apical margin of abdominal sternite VIII widely concave. Aedeagus long, with very wide basal portion, strongly narrowed toward moderately wide median lobe, from apical third gradualy narrowed toward small rounded apex; parameres narrow, slightly broadened apically, distinctly exceeding apex of median lobe, with one short apical and two preapical setae; internal sac very long and narrow, with several very long sclerotized structures in basal portion ( Fig. 22 ). Lateral aspect of the aedeagus as in Fig. 23 .

Female. Apical margins of abdominal tergite VIII and sternite VIII straight or somewhat rounded.

Comparative notes. Altaiodromicus kastcheevi sp. n. can be distinguished from A. schilenkovi by the slightly broader head with slightly shorter temples, finer punctation of the middle portion of the head, and more distinct punctation of the pronotum. It can be easily distinguished from A. schilenkovi by the broader median lobe of the aedeagus, the lack of short setae along inner margin of each paramere, and the presence of large sclerotized structures in basal portion of the internal sac. Based on the slightly elongate antennomeres 4–10, it is somewhat similar to the Himalayan M. brevitarsis , from which it can be distinguished by the shallow interocellar foveae, broader pronotum, and the morphology of the aedeagus.

Distribution. Altaiodromicus kastcheevi sp. n. is known from three localities in Altai Mts. and Dzhungar Mts., Kazakhstan ( Fig. 30 ).

Bionomics. Detailed bionomical data are unknown.

Etymology. The species is named in memory of V.A. Kastcheev (20.12.1953 – 14.07.2012), collector of the type specimens.

Figures

FIGURE 30. Distribution of Microedus in the Middle Asia: M. schilenkovi (circles), M. kastcheevi (squares).

FIGURES 1–5. Habitus of Microedus: 1—M. austinianus (USA: New Hampshire), 2—M. brevitarsis (holotype), 3—M. kastcheevi (paratype, Kazakhstan: Dzhungar Mts.), 4—A. schilenkovi (Russia: Altai, Korgon Mts.), 5—M. sp. (Kashmir). Scale bar: 1.0 mm.

FIGURES 18–23. Aedeagus of Microedus schilenkovi (Figs 18–19: Russia, Altai, Aygulakskiy Mts.; Fig. 20: Russia, Altai, Teletskoye Lake; Fig. 21: Kazakhstan, Tauchilik River) and A. kastcheevi (Figs. 22–23: paratype, Dzhungar Mts.): 18, 20–22— parameral view, 19, 23—lateral view. Scale bar: 0.1 mm.